Figure 3. Maternal obesity combined with a Western-style diet (WSD) increases fetal muscle electron transfer system (ETS) activity but not mitochondrial abundance.

ETS enzymatic activities for mitochondrial (A) complex (C) I, (B) CII, (C) CI+III, and (D) CIV as well as (E) citrate synthase (CS) activity were measured by spectrophotometry in male (M; circles) and female (F; triangles) fetal gastrocnemius muscle from lean/overweight dams that had only received control diet (Ln/CTR; n = 10–11 M, 15–16 F), Ln/WSD (n = 6 M, 5–7 F), and obese dams chronically fed a WSD (Ob/WSD; n = 13 M, 12 F) groups. (F) An estimate of mitochondrial number was calculated as the ratio of expression for the mitochondrial gene, cytochrome B (CYTB), to the nuclear gene, hemoglobin beta (HBB), in fetal muscle from Ln/CTR (n = 9 M, 12 F), Ln/WSD (n = 8 M, 5 F) and Ob/WSD (n = 11 M, 6 F). Values are expressed relative to ribosomal protein S15 (RPS15). All data were analyzed by 2-way ANOVA (maternal group × fetal sex) with post-hoc tests. P values for significant main effects are listed in each graph. Letters are used to indicate significant post-hoc differences. Groups with the same letter are not significantly different from each other. Individual data points and the group mean ± SEM are shown.